Does Topography Influence Millipede&#39;s Abundance and Biomass in an Oriental Beech Forest, Iran?

Abstract BackgroundMillipedes acting as one of the important soil organisms having an important influence on decomposition of vegetation and nutrient cycling and their return process to the soil ecosystem, and they usually can be found under the litter layer within the shallow depths. Topography with changing soil traits and plant’s composition will result in changes in soil biota, by the reaction of microsite condition to topography variables. It has been documented that millipedes are not considered as an exception to this trend, so we aimed at study the changes in millipede’s density and biomass with regard to the landforms and soil depth. We studied the effect of catena shape and slope position and different soil depths on millipede’s abundance and biomass. ResultsThe results of our study indicated that millipedes can affect by topography to high levels, in a way that they are more abundant with higher biomass in humid areas such as V-shaped catena and lower slope position than the C-shaped catena and upper slope positions. We also observed that the biomass and density of millipedes decrease with increasing the soil depth. ConclusionIt appears that the factors such as soil moisture, pH, plant composition, and N are the most important factors in millipede’s abundance and diversity with more emphasis on soil moisture as the main factor.

Site-specific wild oat (Avena fatua L.) management

Canadian Journal of Plant Science ◽

10.4141/cjps2012-007 ◽

2012 ◽

Vol 92 (5) ◽

pp. 923-931 ◽

Cited By ~ 5

Author(s):

H. J. Beckie ◽

S. Shirriff

Keyword(s):

Specific Treatment ◽

Triticum Aestivum L ◽

Avena Fatua ◽

Slope Position ◽

Wild Oat ◽

Herbicide Application ◽

Brassica Napus L ◽

Site Specific ◽

Lower Slope ◽

Beckie, H. J. and Shirriff, S. 2012. Site-specific wild oat ( Avena fatua L.) management. Can. J. Plant Sci. 92: 923–931. Variation in soil properties, such as soil moisture, across a hummocky landscape may influence wild oat emergence and growth. To evaluate wild oat emergence, growth, and management according to landscape position, a study was conducted from 2006 to 2010 in a hummocky field in the semiarid Moist Mixed Grassland ecoregion of Saskatchewan. The hypothesis tested was that wild oat emergence and growth would be greater in lower than upper slope positions under normal or dry early growing season conditions. Three herbicide treatments were imposed on the same plots each year of a 2-yr canola (Brassica napus L.) – wheat (Triticum aestivum L.) sequence: (1) nontreated (weedy) control; (2) herbicide application to upper and lower slope positions (i.e., full or blanket application); and (3) herbicide application to lower slope position only. Slope position affected crop and weed densities before in-crop herbicide application in years with dry spring growing conditions. Site-specific wild oat herbicide application in hummocky fields in semiarid regions may be justified based on results of wild oat control averaged across slope position. In year 2 of the crop sequence (wheat), overall (i.e., lower and upper slope) wild oat control based on density, biomass, and dockage (i.e., seed return) was similar between site-specific and full herbicide treatment in 2 of 3 yr. Because economic thresholds have not been widely adopted by growers in managing wild oat, site-specific treatment in years when conditions warrant may be an appropriate compromise between no application and blanket herbicide application.

Influence of tillage displaced soil on the productivity and yield components of barley in northwest Iran

10.4141/cjss2011-096 ◽

2012 ◽

Vol 92 (4) ◽

pp. 665-672 ◽

Cited By ~ 1

Author(s):

Leila Nazmi ◽

Hossein Asadi ◽

Ruzanna Manukyan ◽

Hamdollah Naderi

Keyword(s):

Field Experiment ◽

Yield Components ◽

Slope Position ◽

Soil Productivity ◽

Slope Gradient ◽

Position Effects ◽

Northwest Iran ◽

Lower Slope ◽

Tillage Erosion ◽

Nazmi, L., Asadi, H., Manukyan, R. and Naderi, H. 2012. Influence of tillage displaced soil on the productivity and yield components of barley in northwest Iran. Can. J. Soil Sci. 92: 665–672. In hilly landforms subject to long-term cultivation, erosion has denuded the upper slope positions of topsoil, and accumulated topsoil in the lower slope positions. Slope gradient and position effects aggregation processes, which in turn impact soil productivity. A field experiment was conducted to assess the tillage-induced soil displacement and its effects on the soil properties and barley (Hordeum vulgare var. Sahand) biomass production for three different landscapes. The study was conducted on a hill slope seeded with barley (1.4–10.1° slope) located in the Mollaahmad watershed of the Ardabil province in northwestern Iran. For this purpose, soil samples were collected from four slope positions in a grassland as well as an agricultural field (dryland). A field experiment was conducted to evaluate the effects of slope gradient and position on barley growth and soil quality. Soil generally had lower organic carbon, available phosphorus, calcium carbonate equivalent, soil water content and mean weight diameter of soil aggregates in the farmland than the grassland, and in the upper slope positions than in the lower slopes. Significantly higher barley growth indices were associated with lower slope positions. Agronomic productivity of the soil was lowest for landscapes with the highest slope gradient. The relationships between tillage erosion and yield components were found to be significant. Spike weight and slope position had the largest contribution for the explanatory capacity of canonical variables (tillage erosion and yield components) estimated when compared with other parameters (slope gradient, dry matter, spike number, grain yield and 1000-grain weight). The findings in this study can be used as a tool to assist farmers, soil and water conservationists, and other policymakers in decision making regarding the use of lands.

Genesis of Solonetzic soils as a function of topography and seasonal dynamics

10.4141/cjss94-029 ◽

1994 ◽

Vol 74 (2) ◽

pp. 207-217 ◽

Cited By ~ 9

Author(s):

J. J. Miller ◽

S. Pawluk

Keyword(s):

Seasonal Dynamics ◽

Slope Position ◽

Seasonal Fluctuations ◽

Topographic Position ◽

Exchangeable Acidity ◽

Sodium Percent ◽

Acidic Conditions ◽

Lower Slope ◽

A Gleyed Black Solonetz at a depressional slope position, a Black Solonetz at a lower slope position, a Black Solodized Solonetz at a mid-slope position, and a Black Solod at an upper slope position in central Alberta, were investigated using chemical, physical and mineralogical techniques to determine the role of topographic position and season in their genesis. Solonization, as indicated by electrical conductivity (EC) values < 4 dS m−1 and exchangeable sodium percent (ESP) values > 15% in the B horizon, was greatest in the Gleyed Black Solonetz, and then decreased in the soils upslope. Solonization occurred during the spring, summer and fall in the B horizon of the Gleyed Black Solonetz and Bnt1 horizon of the Black Solod, and during the spring in the B horizon of the Black Solonetz, Bnt1 horizon of the Black Solodized Solonetz, and Bnt2 horizon of the Black Solod. Solodization, as indicated by the development of Ae and AB horizons, acidic conditions and higher dithionite-extractable Al in the upper sola, and high exchangeable acidity in the upper B horizons, was greatest in the Black Solod at the upper slope position, moderate in the Black Solodized Solonetz at the mid-slope position, and absent in the two soils at the lower slope positions. Solodization as reflected by exchangeable acidity, also exhibited seasonal fluctuations, particularly in the upper B horizons. Seasonal variations of exchangeable Na, Ca and Mg in the B horizons, however, were slight to nonexistent. Topographic position and seasonal fluctuations of soluble salts and exchangeable acidity in the B horizons played a major role in the genesis of soils in this Solonetzic catena. Key words: Solonetzic catena, solonization, solodization, topography, seasonal dynamics

Effects of Landscape Position, Rainfall, and Tillage on Residual Herbicides

Weed Technology ◽

10.1614/wt-d-09-00067.1 ◽

2010 ◽

Vol 24 (3) ◽

pp. 361-368 ◽

Cited By ~ 4

Author(s):

James R. Moyer ◽

Gerald Coen ◽

Robert Dunn ◽

Anne M. Smith

Keyword(s):

Soil Ph ◽

Organic Matter Content ◽

Conventional Tillage ◽

Severe Injury ◽

Slope Position ◽

No Tillage ◽

Tillage Systems ◽

Crop Injury ◽

Lower Slope ◽

The effect of soil properties and weather on herbicide persistence and injury to following crops were studied at a site near Lethbridge, Alberta, Canada, with undulating topography that included no-tillage and conventional tillage systems on adjacent fields. Soil pH ranged from 5.2 (lower slope no-tillage) to 7.8 (upper slope conventional tillage) and soil organic matter content ranged from 2.3% (upper slope conventional tillage) to 4.4% (lower slope no-tillage). During the years when the experiments were conducted rainfall ranged from < 50% of normal to > 150% of normal. During dry years atrazine and metsulfuron severely injured wheat and lentil crops, seeded 1 yr after herbicide application, on upper slope locations. The most severe injury occurred on the upper slope conventional tillage location. In years with high rainfall, no crop injury occurred 1 yr after atrazine and metsulfuron application on either upper or lower slope locations in both tillage systems. Imazamox plus imazethapyr caused almost 100% injury in the lower slope position in the no-tillage system (pH 5.2) in the driest year. Following-crop injury due to the imidazolinone herbicides decreased with increasing rainfall and increasing soil pH. The most severe injury to following crops seemed to occur when herbicide dissipation was dependent on microbial activity and rainfall was below normal.

Controls on the spatial distribution of soil moisture and solute transport in a sloping reclamation cover

Canadian Geotechnical Journal ◽

10.1139/t07-099 ◽

2008 ◽

Vol 45 (3) ◽

pp. 351-366 ◽

Cited By ~ 24

Author(s):

Chris Kelln ◽

S. Lee Barbour ◽

Clara Qualizza

Keyword(s):

Spatial Distribution ◽

Soil Moisture ◽

Preferential Flow ◽

Salt Transport ◽

Soil Matrix ◽

Groundwater Flux ◽

Through Diffusion ◽

Moisture Conditions ◽

Lower Slope ◽

A detailed field study was conducted to map the spatial distribution of soil moisture and salt transport within a sloping clay-rich reclamation cover overlying a saline-sodic shale overburden landform. The soil moisture data suggest that: lower-slope positions are wetter in spring due to the down-slope movement of surface run-off; infiltration occurs via preferential flow paths while the ground is frozen; and, interflow occurs along the cover–shale surface when the ground thaws. Soil moisture conditions also remain wetter in lower-slope positions throughout the summer and fall. Salt transport from the shale into the overlying cover is affected predominantly by soil moisture conditions and lateral groundwater flux. Quasi one-dimensional modelling of in situ profiles of pore-water Na+ concentration demonstrate that: (i) increased soil moisture conditions in lower-slope positions accelerate salt transport into the cover through diffusion; (ii) snow melt infiltration water bypasses the soil matrix higher in the cover profile; (iii) drier conditions in the mid- and upper-slope positions limit salt transport through diffusion; (iv) advection accelerates upward salt transport in lower-slope positions; and, (v) interflow and (or) deep percolation are key mechanisms mitigating vertical salt movement in lower- and upper-slope positions.

Unsaturated water flux at mid and lower slope positions within an inclined landscape of the Dark Brown soil zone in southern Alberta

10.4141/cjss-2014-058 ◽

2015 ◽

Vol 95 (1) ◽

pp. 27-36 ◽

Cited By ~ 1

Author(s):

J. J. Miller ◽

D. S. Chanasyk

Keyword(s):

Soil Moisture ◽

Root Zone ◽

Flow Direction ◽

Water Flux ◽

Slope Position ◽

Water Fluxes ◽

Brown Soil ◽

Soil Zone ◽

Southern Alberta ◽

Lower Slope

Miller, J. J. and Chanasyk, A. S. 2015. Unsaturated water flux at mid and lower slope positions within an inclined landscape of the Dark Brown soil zone in southern Alberta. Can. J. Soil Sci. 95: 27–36. Little research has quantified vertical-unsaturated water flux below the root zone for mid and lower slope positions within inclined, low-relief, and longer-slope landscapes of the Dark Brown soil zone of the Canadian prairies. We measured soil moisture (0.23–1.22 m) in the field at mid and lower slope positions in southern Alberta from May to October in 1985 and 1986. Undisturbed soil cores were taken from soil horizons and saturated hydraulic conductivity and soil moisture retention were determined in the laboratory. Vertical-unsaturated water flux below the root zone was calculated between 1.07 and 1.22 m depths below ground surface using the hydraulic gradient method. Water fluxes for the 2 yr ranged from <10−11 to 10−10 m s−1 at the mid slope position, and from <10−11 m s−1 to 10−9 m s−1 at the lower slope position, and were consistent with some other studies. Cumulative water flux was dominantly downward (−2.2 to −3.4 mm) at the mid slope position and this flow direction was consistent with this Orthic Dark Brown Chernozemic soil that was located in a “recharge area”. Cumulative water flux was dominantly upward at the lower slope position in 1985 (1.4 mm) and dominantly downward but of very low magnitude in 1986 (−0.1 mm), and this flow direction was consistent with this saline Gleyed Regosol and “saline seep”. Cumulative water fluxes as a percentage of annual precipitation were 0.8 to 1.8% at the mid slope position and 0.3 to 0.5% at the lower slope position.

Interpretation of soil enzyme activities in a comparison of tillage practices along a topographic and textural gradient

10.4141/s99-034 ◽

2000 ◽

Vol 80 (1) ◽

pp. 71-79 ◽

Cited By ~ 26

Author(s):

D. W. Bergstrom ◽

C.M. Monreal ◽

A. D. Tomlin ◽

J.J. Miller

Keyword(s):

Enzyme Activities ◽

Soil Enzyme ◽

Slope Position ◽

Soil Enzyme Activities ◽

Tillage Practice ◽

Tillage Practices ◽

No Till ◽

Ap Horizon ◽

Lower Slope ◽

Assessment of the impacts of soil conservation practices requires measurement of the resulting changes in soil quality at scales inclusive of soil variability comparable to that of typical farms. The objective of this study was to compare changes in six soil enzyme activities (urease, glutaminase, phosphatase, arylsulfatase, β-glucosidase and dehydrogenase) and organic carbon (OC) content resulting from implementation of no-till along a topographic and soil textural gradient. Activities of β-glucosidase, glutaminase, phosphatase and arylsulfatase, and OC content were greater in coarse-textured soils at a lower slope-position than in fine-textured soil at an upper slope-position. Tillage practice influenced activities of urease, glutaminase, β-glucosidase and dehydrogenase but not OC content. The effect of tillage practice on enzyme activities was influenced by sampling depth and slope-position. Phosphatase and arylsulfatase activities of the Ap horizon behaved as indices of soil organic matter (SOM) content along the topographic gradient. Urease and dehydrogenase activities behaved as indices of soil biochemical activity within the Ap horizon. When interpreted in these terms, soil enzyme activities are comparable to other integrative measurements and as such describe system behavior and attributes. Key words: Soil enzyme activity, no-till, topographic position

Slope Position Rather Than Thinning Intensity Affects Arbuscular Mycorrhizal Fungi (AMF) Community in Chinese Fir Plantations

Forests ◽

10.3390/f11030273 ◽

2020 ◽

Vol 11 (3) ◽

pp. 273 ◽

Cited By ~ 1

Author(s):

Xuelei Xu ◽

Xinjie Wang ◽

Michelle Cleary ◽

Ping Wang ◽

Nini Lu ◽

...

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Community Composition ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Chinese Fir ◽

Slope Position ◽

Thinning Intensity ◽

Amf Diversity ◽

Lower Slope ◽

Background and Objectives: Arbuscular mycorrhizal fungi (AMF) play a crucial role in individual plant capability and whole ecosystem sustainability. Chinese fir, one of the most widely planted tree species in southern China, forms associations with AMF. However, it is still unclear what impacts thinning management applied to Chinese fir plantations has on the structure and diversity of soil AMF communities. This research attempts to bridge this knowledge gap. Materials and Methods: A thinning experiment was designed on different slope positions in Chinese fir plantations to examine the impacts of slope position and thinning intensity on colonization, diversity, and community composition of AMF. Results: Our research showed that the altitudinal slope position had significant effects on colonization, diversity, and community composition of AMF in Chinese fir plantations. In addition, the interaction between slope position and thinning intensity had significant effects on AMF diversity. Colonization by AMF on the lower slope position was significantly higher than on the upper slope position, while AMF diversity on the upper slope position was higher than on the middle and lower slope positions. Glomus was the most abundant genus in all slope positions, especially on the middle and lower slope positions. The relative abundance of Diversispora was significantly different among slope positions with absolute dominance on the upper slope position. Scutellospora was uniquely found on the upper slope position. Furthermore, soil Mg and Mn contents and soil temperature positively affected AMF community composition at the operational taxonomic unit (OTU) level. Conclusions: These findings suggested that slope position should be considered in the management of Chinese fir plantations. Furthermore, both chemical fertilization and AMF augmentation should be undertaken on upper hill slope positions as part of sustainable management practices for Chinese fir plantations.

Influence of trees and topography on soil water content in semi-arid region, the case of an agro-silvo-pastoral ecosystem dominated by Faidherbia albida (Senegal)

10.5194/egusphere-egu21-9060 ◽

2021 ◽

Author(s):

Djim Diongue ◽

Didier Orange ◽

Waly Faye ◽

Olivier Roupsard ◽

Frederic Do ◽

...

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Soil Layer ◽

Rainfall Infiltration ◽

Faidherbia Albida ◽

Lower Slope ◽

<p>Vegetation strongly affects the water cycle, and the interactions between vegetation and soil moisture are fundamental for ecological processes in semiarid regions. Therefore, characterizing the variation in soil moisture is important to understand the ecological sustainability of cropping systems towards food security. The present study aims at exploring factors and mechanisms influencing soil moisture variability in the Faidherbia albida (FA) parkland at Sob basin located in the center of Senegal [1]. Volumetric soil moisture content at multiple depths was monitored at 15 locations distributed along a transect (upper slope, mid-slope and lower slope) and different FA tree position (under, at the limit and outside canopy) from August to October 2020. A portable TRIME Time Domain Reflectometry (TDR) Tube Probe (IMKO, Germany) was used to determine soil volumetric moisture content while being placed at specific depth intervals inside a PVC access tube set up at each location. Soil moisture was monitored at 10 cm interval from 20 to 420 cm during the rainy season from July to October 2020. Results of soil moisture profiles along the transects exhibit two main zones based on the standard deviation (SD) and the inflection of the coefficient of variation (CV): shallow soil moisture (SSM) and deep soil moisture (DSM). For SSM observed at 20-60 cm of the soil layer, both mean soil moisture and SD increase with depth, the lowest mean value (8%) being observed at the top surface. This soil layer is influenced by rainfall infiltration and daily evaporation. For DSM observed at 70-420 cm, the moisture pattern can be further divided into 4 soil sublayers taking the mean soil moisture vertical distribution as reference: (i) a rainfall infiltration layer (70-160 cm) which appears mainly influenced by cumulative rainfall infiltration in addition to transpiration of grassland and crops (shallow root system); (ii) a rainfall-transpiration layer (170-250 cm) which is still an infiltration layer but more influenced by crops transpiration; (iii) a transpiration layer (260-350 cm) which can be recharged by rainfall infiltration during heavy rainfall and supply deep root system; and (iv) deep transpiration layer (360-400 cm) which has DSM that can be influenced by extremely deep root vegetation such as FA. The factors influencing the soil water content varied with the topography. The soil water content SWC (mean and median value of 27.2 and 29.6% respectively) in the lower slope was significantly higher than that at middle (mean and median value of 14.4 and 13.2 % respectively) and upper slope (mean and median value of 16.8 and 18.4 % respectively). At last, soil water content was positively correlated with the distance from the FA, regardless the slope. The higher water content for both SSM and DSM was observed outside the FA canopy. This result refutes the initial hypothesis of higher SWC under trees and support a more detailed analysis of the infiltration capacity in relationship with the FA position.</p><div> <div> <p>[1] Faidherbia-Flux : https://lped.info/wikiObsSN/?Faidherbia-Flux</p> </div> </div>

Slope position and subsoiling effects on soil water and spring wheat yield

10.4141/s95-067 ◽

1997 ◽

Vol 77 (1) ◽

pp. 83-90 ◽

Cited By ~ 30

Author(s):

B. G. McConkey ◽

D. J. Ulrich ◽

F. B. Dyck

Keyword(s):

Water Use Efficiency ◽

Soil Water ◽

Water Use ◽

Spring Wheat ◽

Slope Position ◽

Crop Water ◽

Crop Water Use ◽

Use Efficiency ◽

Lower Slope ◽

A study was conducted on a 4-m-high ridge in southwestern Saskatchewan to determine the relationship of slope position with the soil water regime and spring wheat (Triticumaestivum L.) production and to determine if those relationships were altered by subsoiling. In all years, available soil water in the spring to 120 cm increased significantly with distance upslope. This pattern was attributed to residual subsoil water in the rooting zone that had not been used by previous crops in a long-term crop-fallow rotation. After 3 yr of annual spring wheat production, soil water to 1.2 m at all slope positions approximately equalled the water content wilting point (4.0 MPa) water content, showing this residual water had been largely consumed. Apparent use of soil water between seeding and harvest at the upper slope positions was equal to or greater than that at the lower slope positions. Over-winter soil water conservation, using tall (≥ 30-cm-high) wheat stubble for snow trapping, at the upper slope positions was equal to or greater than that at the lower slope positions. In the non-drought years of 1987 and 1989, wheat yields and crop water use efficiency increased significantly with distance downslope. Since these slope effects were not related to water use or availability, they were attributed to higher soil productivity, probably related to more historical net erosion with distance upslope. During the drought year of 1988, wheat yields and water use efficiency were greatest at the upslope positions, but these results were confounded by uneven crop emergence. Subsoiling to 35 cm or deeper increased the amount and depth of infiltration of water in years with near-average November–April precipitation. Subsoiling had little effect on wheat yields and no effect on crop water use. Key words: Landscape, wheat, productivity, soil moisture